U.S. patent number 7,208,460 [Application Number 10/948,971] was granted by the patent office on 2007-04-24 for multi component controlled delivery system for soap bars.
This patent grant is currently assigned to Salvona IP, LLC. Invention is credited to Adi Shefer, Samuel Shefer.
United States Patent |
7,208,460 |
Shefer , et al. |
April 24, 2007 |
Multi component controlled delivery system for soap bars
Abstract
The present invention relates to an improved controlled delivery
system that can be incorporated in soap bars to enhance deposition
of active ingredients and sensory markers onto skin. The carrier
system also provides controlled release or prolonged release of
these actives from the skin over an extended period of time. The
controlled delivery system of the present invention comprises
substantially free-flowing, powder formed of solid hydrophobic,
positively charged, nanospheres of encapsulated active ingredients,
that are encapsulated in moisture sensitive microspheres. The high
cationic charge density of the nanosphere improves deposition of
active ingredients onto skin. The high cationic charge density on
the nanosphere surface is created by incorporating a cationic
conditioning agent into the solid hydrophobic matrix of the
nanospheres, by incorporating a cationic charge "booster" in the
moisture sensitive microsphere matrix, or by using a cationic
conditioning agent in the nanosphere matrix in conjunction with a
cationic charge "booster" in the microsphere matrix. The invention
also pertains to soap products comprising the controlled release
system of the present invention.
Inventors: |
Shefer; Adi (Dayton, NJ),
Shefer; Samuel (Dayton, NJ) |
Assignee: |
Salvona IP, LLC (Dayton,
NJ)
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Family
ID: |
36119222 |
Appl.
No.: |
10/948,971 |
Filed: |
September 24, 2004 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050065047 A1 |
Mar 24, 2005 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10286143 |
Nov 1, 2002 |
6825161 |
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10133833 |
Apr 26, 2002 |
6740631 |
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Current U.S.
Class: |
510/441; 424/451;
424/458; 424/485; 424/486; 510/101; 510/440; 512/4 |
Current CPC
Class: |
A61K
8/11 (20130101); A61Q 19/10 (20130101); B82Y
5/00 (20130101); C11D 1/62 (20130101); C11D
3/505 (20130101); C11D 9/00 (20130101); C11D
9/26 (20130101); C11D 9/36 (20130101); C11D
9/442 (20130101); C11D 17/0039 (20130101); C11D
17/006 (20130101); A61K 8/0283 (20130101); A61K
2800/413 (20130101) |
Current International
Class: |
A61K
9/51 (20060101) |
Field of
Search: |
;510/438,440,441,442 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Federal Register, vol. 43, No. 166--Friday, Aug. 25, 1978, pp.
38206-38269. cited by other .
Balassa, L et al., "Microencapsulation in The Food Industry", CRC
Critical Reviews in Food Technology, pp. 245-265, Jul. 1971. cited
by other .
Barreto, Paul, "Perfumes for Specialties", Soap & Chemical
Specialties, pp. 66-67 & 155, Dec. 1966. cited by other .
Malceny, Robert T., "Spray Dried Perfume", Soap and San Chem., Jan.
1958, pp. 135-145. cited by other .
Richmond, James M., "Cationic Surfactants", Marcel Dekker, Inc.,
New York and Basel, 1990, pp. iii-I. cited by other.
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Primary Examiner: Hardee; John R.
Attorney, Agent or Firm: Mathews, Shepherd, McKay &
Bruneau, P.A.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser.
No. 10/286,143 filed Nov. 1, 2002 now U.S. Pat. No. 6,825,161,
which is a continuation-in-part of U.S. patent application Ser. No.
10/133,833, filed Apr. 26, 2002 now U.S. Pat. No. 6,740,631, the
contents of which are hereby incorporated by reference into this
application.
Claims
What is claimed is:
1. A controlled delivery system for soap comprising: a plurality of
solid positively charged nanospheres, each of said solid
nanospheres comprising an effective amount of a first active agent,
said solid nanospheres are formed of hydrophobic material selected
from one or more of the group consisting of natural wax,
regenerated wax, synthetic wax, animal wax, vegetable wax, mineral
wax, natural wax and silicon copolymer, and synthetic wax and
silicon copolymer, said plurality of nanospheres being encapsulated
in a moisture sensitive microsphere, said moisture sensitive
microsphere is formed of a moisture sensitive matrix material,
wherein said moisture sensitive matrix material releases said
nanospheres upon contact with moisture.
2. The system of claim 1 wherein said hydrophobic material has a
melting point in the range of about 20 degrees C. to about 90
degrees C.
3. The system of claim 1 further comprising a second active agent
encapsulated in said moisture sensitive matrix material wherein
said moisture sensitive matrix material releases said second active
agent upon contact with moisture.
4. The system of claim 3 wherein said second active agent is the
same or different than said first active agent, said first and
second active agents being selected from the group consisting of a
fragrance, cosmetic agent, dermatological agent and pharmaceutical
agent.
5. The system of claim 3 wherein said second active agent comprises
one or more agents selected from the group consisting of:
anti-oxidants; free radical scavengers; moisturizers;
depigmentation agents; reflectants; humectants; antimicrobial
agents; antibacterial agents; allergy inhibitors; anti-acne agents;
anti-aging agents; anti-wrinkling agents, antiseptics; analgesics;
keratolytic agents; anti-inflammatory agents; fresheners; healing
agents; anti infective agents; inflammation inhibitors; wound
healing promoters; peptides, polypeptides; proteins; deodorants;
antiperspirants; skin emollients; skin moisturizers; tanning
agents; skin lightening agents; antiflingals; depilating agents;
counterirritants; poison ivy agents; poison oak agents; burn
products; make-up preparations; vitamins; amino acids and their
derivatives; herbal extracts; cooling agents; heating agents; skin
conditioners; chelating agents; cell turnover enhancers; coloring
agents; sunscreens; nourishing agents; moisture absorbers; sebum
absorbers; and skin penetration enhancers.
6. The system according to claim 3 wherein said moisture sensitive
material upon contact with said moisture releases said second
active agent to provide a burst and said first active agent is
released continuously thereafter for an extended period of
time.
7. The system according to claim 6 wherein the extended period of
time is in the range of a few hours to a period of a few weeks.
8. The system according to claim 1 wherein said moisture sensitive
material is selected from the group consisting of polyvinyl
pyrrolidone, water soluble cellulose, polyvinyl alcohol, ethylene
maleic anhydride copolymer, methyl vinyl ether maleic anhydride
copolymer, polyethylene oxide, polyamide, polyester, copolymers or
homopolymers of acrylic acid, polyacrylic acid, polystyrene acrylic
acid copolymer, starch derivatives, polysaccharide, hydrocolloid,
natural gum, protein, and mixtures thereof.
9. The system of claim 8 wherein said polyvinyl alcohol has a
degree of hydrolysis from about 75% to about 99%.
10. The system of claim 1 wherein said first active agent is one or
more of a fragrance, cosmetic agent, dermatological agent or
pharmaceutical agent.
11. The system of claim 1 wherein said first active agent comprises
one or more agents selected from the group consisting of:
anti-oxidants; free radical scavengers; moisturizers;
depigmentation agents; reflectants; humectants; antimicrobial
agents; antibacterial agents; allergy inhibitors; anti-acne agents;
anti-aging agents; anti-wrinkling agents, antiseptics; analgesics;
keratolytic agents; anti-inflammatory agents; fresheners; healing
agents; anti infective agents; inflammation inhibitors; wound
healing promoters; peptides, polypeptides; proteins; deodorants;
antiperspirants; skin emollients; skin moisturizers; tanning
agents; skin lightening agents; antifungals; depilating agents;
counterirritants; poison ivy agents; poison oak agents; burn
products; make-up preparations; vitamins; amino acids and their
derivatives; herbal extracts; cooling agents; heating agents; skin
conditioners; chelating agents; cell turnover enhancers; coloring
agents; sunscreens; nourishing agents; moisture absorbers; sebum
absorbers; and skin penetration enhancers.
12. The system of claim 1 wherein said first active agent is a
fragrance and one or more of a vitamin, antimicrobial agent,
antifungal agent, anti-inflammatory agent, anti-acne agent,
cosmetic soothing active, skin lightening active, sunscreen active,
anti-itch active, antioxidant or skin conditioner.
13. The system of claim 1 wherein said moisture sensitive matrix
material is formed of about 1% to about 80% polyvinyl alcohol by
weight of the matrix material and about 1% to about 80%
polysaccharide by weight of the matrix material.
14. The system of claim 1 wherein said microsphere has a size of
from about 2.0 to about 50 microns.
15. The system according to claim 1 wherein each of said
nanospheres has an average size of about 0.05 to about 2
microns.
16. An article of manufacture comprising said system of claim 1.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved controlled release
carrier system that can be incorporated into soap bars that
enhances deposition of active ingredients as well as fragrances
onto skin and which prolongs the release of active ingredients and
fragrances from the skin over an extended period of time.
2. Description of the Related Art
Consumer acceptance of soap bars is determined not only by the
performance achieved with these products but the aesthetics
associated therewith. Fragrance is an important aspect of the
successful soap bars and they are being utilized, in addition to
imparting an aesthetically pleasing odor, to convey to the consumer
the product performance and effectiveness (i.e., the skin is clean,
etc.). Recently, soap bars are utilized not only to clean and
disinfect the skin, but also to impart long lasting malodor
coverage and the performance features expected from these products
are similar to those of deodorants.
Fragrances are typically added to soap bars to provide a fresh,
clean impression for these products as well as the skin treated
with these products. While the fragrance does not add to the
performance of soap bars, it does make these products more
aesthetically pleasing and the consumer has come to expect such
products to have a pleasing odor. The fragrance plays a major, and
often determining, role for the consumer in selecting and
purchasing the soap bars. Consumers are becoming increasingly
educated and expect a high level of sophistication in their soaps.
Many consumers would prefer for the fragrance or the disinfecting
actives, present in these products, to be deposited on the skin and
remain there for an extended period of time to convey a lasting
impression of freshness. Fragrance creation for soaps is restricted
not only by considerations such as availability and cost, but also
by compatibility of the fragrance ingredients with other components
in the product composition and the ability of the fragrance
ingredients to deposit onto the skin and survive the rinse process.
Furthermore, large amount of fragrance is being lost during
washing. Practice has shown that when currently available products
are used, a large fraction of the fragrance is lost during the
rinse process due to the solubility of certain fragrance
ingredients in aqueous washing compositions, and the fraction of
the fragrance which was deposited, quickly evaporates, due to the
volatility of fragrance ingredients.
Water soluble polymers have also been used to encapsulate fragrance
oils. Such capsules have proved useful in releasing perfume in
deodorants. However, such capsules have not been commercially
successful in extended release of perfume from skin. U.S. Pat. Nos.
5,770,556 and 5,955,409 disclose a process for making bar
compositions having enhanced deposition of benefit agent. The
patents relate to a process in which specific powder adjuvants
comprising (a) benefit agents, (b) a carrier (e.g., soluble or
partially soluble starches, water soluble amorphous solids or
semi-crystalline water soluble solids), (c) water and (d) optional
deposition/processing aids are first prepared and then mixed with
bar chips prior to milling, extruding and stamping the bars. The
carrier component disclosed by U.S. Pat. No. 5,770,556 is any water
soluble starch including both partially soluble starches (such as
corn or potato starch) and, more preferably, "true" water soluble
starches, i.e., starches in which at least 10% by wt. or greater
solution of starch in water will dissolve to form a clear or
substantially clear solution. Examples of such include
maltodextrin. The carrier may also be a semi-crystalline water
soluble solid such as, for example, gelatin. The carrier compound
generally will comprise about 15% to 98%, preferably 30% to 50% of
the powder composition. These carrier materials will quickly
dissolve in water (especially maltodextrins) to release the active
and have little chance to enhance deposition of active ingredients
onto the skin and sustain their release rate on the skin.
U.S. Pat. No. 5,876,755 discloses a water-sensitive matrix material
which can be starch, modified starch, maltodextrin, cyclodextrin,
gums, resins, synthetic or semisynthetic polymers such as polyvinyl
pyrrolidine (PVP), polyvinylalcohol (PVA) and cellulose esters, and
combinations of these materials. The preferred matrix material
comprises modified starch. The encapsulating material (i.e., the
encapsulated substance within the water-sensitive matrix) is
conveniently prepared by spray drying, and is typically particulate
so that the composition as a whole is particulate in nature.
U.S. Pat. Nos. 4,803,195 and 5,508,259 also disclose a water
soluble encapsulation system that can be incorporated in soap bars.
The matrix material utilized in the above patents comprises: a. a
solid film-forming substrate chosen from polyvinyl acetate,
polyvinyl alcohol, dextrins, natural or modified starch, vegetable
gums, pectins, xanthans, carboxymethylcellulose, methylcellulose,
hydroxymethylcellulose and lipoheteropolysaccharides, and b. an
emulsifying agent chosen from mono- or diglycerides of fatty acids,
esters derived from the combination of fatty acids with sorbitol or
a saccharide, or their alkoxylated derivatives, or an ester of
tartaric, citric, ascorbic or lactic acid. Again, these carrier
materials will quickly dissolve in water (especially maltodextrins)
to release the active and have little chance to enhance deposition
of active ingredients onto the skin and sustain their release rate
on the skin.
U.S. Pat. No. 4,749,501 discloses a solid soap composition
comprising a soap base and microcapsules dispersed therein, said
microcapsules are prepared by using a hydrophobic liquid as a core
material, forming microcapsules by covering the hydrophobic liquid
with coacervate of a hydrophilic material, and then adding an
electrolyte to a solution having the microcapsules dispersed
therein in an amount of 8 to 100 parts by weight to 100 parts by
weight of the water used in the microcapsules to dehydrate the
microcapsule films. The hydrophilic coacervate is an anionic
hydrophilic high molecular weight substance is gum arabic, alkali
metal salt of carboxymethyl cellulose, sodium alginate,
carrageenan, styrene-maleic anhydride copolymer, methyl vinyl
ether-maleic anhydride copolymer, acrylic acid copolymer,
polyvinylbenzene sulfonic acid, carboxymethyl starch or mixtures
thereof. The microcapsules hardly disintegrate during the soap
production process but do disintegrate during the use of the soap
composition when contacted with water. This type of controlled
release system has the limitation of not working with all type of
fragrance ingredients, especially not with fragrance ingredients
that are relatively water-soluble and do not deposit into the
skin.
A similar system is described in U.S. Pat. No. 6,248,703 which
discloses bar compositions comprising a non-water soluble benefit
agent core surrounded by a friable coating comprising the reaction
product of (1) an amine selected from urea and melamine; and (2) an
aldehyde selected from formaldehyde, acetaldehyde and
glutaraldehyde; and mixtures of the amines and the aldehydes;
wherein the capsules are strong enough to survive a soap extrusion
process but sufficiently friable to break upon use of the bar by
the consumer.
Perfumes have been adsorbed onto various materials such as silica
and cyclodextrins to deliver perfume in soap bars. U.S. Pat. No.
5,723,420 discloses a personal cleansing bar compositions which
contains a fragrance-releasing complex and a bar carrier. The
fragrance-releasing complex contains a hydrophilic inorganic porous
fragrance carrier and a fragrance impregnated within the fragrance
carrier. Inorganic carriers include amorphous silica, precipitated
silica, fumed silica and aluminosilicates such as zeolite and
alumina. Another type of inorganic carrier suitable for use in the
present invention include cyclodextrin. This system has the
drawback that the fragrance oil is not sufficiently protected and
is frequently lost or destabilized during processing.
Attempts to enhance deposition of fragrance onto skin have been
described in U.S. Pat. No. 5,476,660 which discloses compositions
to deposit an active substance on a target surface. The active
substance is left on the surface after the product is rinsed off
the surface. The preferred deposition is from compositions
containing an anionic or nonionic active in the co-presence of an
anionic surfactant. The compositions contain carrier particles
having a zwitterionic or cationic surface and a plurality of
outwardly protruding filaments containing charged organocarbyl
groups. The term "zwitterionic" as described in this patent means a
mixture of cationic and anionic (not necessarily neutral); thus the
surface of the zwitterionic particles, have both cationic and
anionic groups (i.e., positively charged and negatively charged
organocarbyl groups). The filaments are formed from an emulsion
comprising molten wax, an anionic surfactant and a cationic
surfactant. The active substance is contained within the carrier
particles.
The major challenge in designing controlled delivery systems for
soap bars is maximizing the deposition of the system comprising the
active ingredients onto the skin. There remains a need in the art
for an efficient controlled delivery system, to effectively deposit
active ingredients, as well as fragrances, onto skin and for a
method to "boost" the overall charge density of particles thereby
providing enhanced deposition onto the skin.
The prior art of which applicant is aware does not set forth a
fragrance controlled release system that can be incorporated in a
soap bar to enhance deposition of active ingredients, as well as
fragrances, especially not for fragrance ingredients that are more
soluble into the aqueous phase of the washing compositions and do
not deposit onto the skin. There is also a need for a fragrance
carrier system, for soap bars, that will allow using a wider range
of fragrance ingredients that are currently not substantive on skin
from a soap bar application and improved fragrance substantivity
and longevity onto the skin. It is desirable to provide a control
release system for overcoming these limitations. It is also
desirable to provide a method using an efficient and economical
process for effectively delivering a broad range of fragrances and
other ingredients onto skin and yields a high impact fragrance
"burst" upon washing and a prolonged fragrance release from the
skin over an extended period of time.
SUMMARY OF THE INVENTION
The present invention relates to an improved controlled delivery
system for active ingredients and sensory markers from soap bars,
to enhance deposition of the active ingredients and sensory markers
onto the skin and extend their release rate over a prolonged period
of time. The controlled delivery system of the present invention is
a multi-component system comprising of positively charged solid
hydrophobic nanospheres encapsulated in a moisture sensitive
microsphere. Active ingredients, as well as sensory markers such as
fragrances, can be incorporated in the nanosphere matrix, in the
microsphere matrix, or in both the nano and microsphere matrices.
The nanosphere surface has high cationic charge density to improve
the deposition of the nanospheres onto the skin. The high cationic
charge density on the nanosphere surface is created by
incorporating a cationic conditioning agent into the solid
hydrophobic matrix of the nanospheres, by incorporating a cationic
charge "booster" in the water sensitive microsphere matrix, or by
using a cationic conditioning agent in the nanosphere matrix in
conjunction with a cationic charge "booster" in the microsphere
matrix. The delivery system of the present invention also yields a
high impact fragrance "burst" upon wash with the system and
provides controlled release or prolonged fragrance release from the
treated skin over an extended period of time.
In one embodiment, the present invention provides an improved
fragrance carrier system for soap bars which has improved fragrance
substantivity to bring the fragrance onto skin that has been washed
with the soap bar comprising the fragrance carrier system. In the
fragrance industry, the term "substantivity" refers to the
deposition of the fragrance on the skin and the retention and
perception of the fragrance on skin treated with the soap bar. The
fragrance carrier system of the present invention provides cationic
surface-active agents to allow a wide range of fragrances and
fragrance ingredients to be compatible within the carrier
composition and increase the substantivity of fragrances and
fragrance ingredients that are currently not substantive on skin
after wash with conventional soap bars. The fragrance-carrier
system yields a high impact fragrance "burst" upon wash and
provides prolonged fragrance release over an extended period of
time. In addition, the production of the carrier system utilizes
minimum processing steps and is efficient and economical.
The carrier system of the present invention is a free-flowing,
powder formed of solid hydrophobic positively charged nanospheres
comprising various active ingredients, as well as fragrances, that
are encapsulated in a moisture sensitive microspheres,
characterized by:
(i) protection of the active ingredients, as well as the volatile
constituents of the fragrance, during storage, until needed;
(ii) yield high impact fragrance "burst" upon wash;
(iii) moisture triggered release of the nanospheres comprising the
active ingredients, as well as the fragrance, in response to
moisture (upon wash),
(iv) enhanced deposition of active ingredients and fragrances onto
skin; and
(v) prolonged release of active ingredients and fragrances from the
skin over an extended period of time.
The invention also provides a method for producing a multi
component controlled release system of the present invention
including active ingredients and a fragrance that comprises the
steps of:
(i) incorporating a cationic conditioning agent, active
ingredients, and fragrance into the solid hydrophobic
nanospheres;
(ii) forming an aqueous mixture comprising of one or more active
agents, a fragrance, the nanospheres, a cationic charge booster,
and a moisture sensitive material, such as, starch derivatives,
natural gums, polyvinyl alcohol, proteins, hydrocolloids, or
mixture of thereof; and
(iii) spray drying the mixture to form a dry powder
composition.
The invention further provides a process for producing the multi
component controlled release system of the present invention that
comprises the steps of:
(i) heating hydrophobic materials to a temperature above the
melting point of the materials to form a melt;
(ii) dissolving or dispersing a cationic conditioning agent into
the melt;
(iii) dissolving or dispersing a first fragrance and a first active
agent into the melt;
(iv) dissolving or dispersing a second active agent, a second
fragrance, a cationic charge booster, and moisture sensitive
material, such as, starch derivatives, natural gums, polyvinyl
alcohol, proteins, hydrocolloids, or mixture of thereof, in the
aqueous phase;
(v) heating the composition to above the melting temperature of the
hydrophobic material;
(vi) mixing the hot melt with the aqueous phase to form a
dispersion;
(vii) high shear homogenization of the dispersion at a temperature
above the melting temperature until a homogeneous fine dispersion
is obtained having a sphere size of from about 1 micron to about 2
microns;
(viii) cooling the dispersion to ambient temperature; and
(ix) spray drying the emulsified mixed suspension to form a dry
powder composition.
The incorporation of spray dried nanospheres comprising fragrances
and other active agents encapsulated within a moisture sensitive
matrix in soap bars was found to enhance fragrance deposition onto
skin, and to extend the release rate of these fragrances and active
ingredients over an extended period of time. In an alternate
embodiment, a controlled release composition is formed of
hydrophobic nanospheres incorporating active agents. It has been
found that a key to maximizing deposition of the system onto the
skin is optimized particle size of the nanospheres of the present
invention to ensure that the particles stay on the skin and have a
sufficiently high cationic charge density on the particle surface
to maximize ionic interaction between the particles and the
skin.
It is believed that the cationic charge groups on the nanospheres
surface become associated, in use of the composition, with the skin
and assist in adhering the nanospheres onto skin during the wash
through both sphere entrainment and electrostatic interactions to
effectively deliver fragrance onto skin and sustain fragrance
release rate. The hydrophobic matrix sustains the diffusion rate of
the fragrance through the nanospheres and enables the fragrance to
be released from the skin over an extended period of time.
The invention also provides soap bars comprising the multi
component controlled release system of the present invention. Skin
treated with a soap bar comprising the multi component controlled
release system of the present invention was observed to exhibit a
high level of fragrance (high odor intensity) and fragrance
perception on skin (the level of fragrance and fragrance perception
on skin) has been observed to perceived over an extended period of
time, such as about 48 hours.
The present invention addresses the foregoing need to increase the
deposition of wide range of fragrances and active ingredients onto
skin and prolong their release so that the skin remains
aesthetically pleasing for an extended period of time by employing
an advanced carrier system to deposit the fragrance and other
active ingredients onto the skin.
The carrier system of the present invention can be incorporated
into any soap bar product and soap compositions and provide
long-term storage stability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the controlled release system of
the present invention upon contact with moisture.
DETAILED DESCRIPTION
The present invention features a method of controlling the release
rate of an active agent, as well as fragrances in soap bars,
yielding a high impact fragrance "burst" upon wash and providing
fragrance release over an extended period of time. A multi
component release system of the present invention is a free-flowing
powder formed of solid hydrophobic, positively charged, nanospheres
that are encapsulated in a moisture sensitive microsphere, as shown
in FIG. 1. Active ingredients, as well as a fragrance, can be
incorporated in the nanosphere matrix, in the microsphere matrix,
or in both the nano and microsphere matrices. The microsphere can
encapsulate the same or different active ingredients and
fragrances. The high cationic charge density on the nanosphere
surface improves deposition of the nanospheres onto skin. The high
cationic charge density on the nanosphere surface is created by
incorporating a cationic conditioning agent into the solid
hydrophobic matrix of the nanospheres, by incorporating a cationic
charge "booster" in the water sensitive microsphere matrix, or by
using a cationic conditioning agent in the nanosphere matrix in
conjunction with a cationic charge "booster" in the microsphere
matrix. The term "spheres" is intended to describe solid,
substantially spherical particulates. It will be appreciated that
other shapes can be formed in accordance with the teachings of the
present invention and are included in the term sphere.
The multi-component controlled release system of the present
invention can comprise from about 1% to about 50% by weight
hydrophobic matrix, from about 1% to about 50% by weight moisture
sensitive matrix, from about 0% to about 10% by weight cationic
charge booster, from about 0.01% to about 10% by weight cationic
conditioning agents, from about 1% to about 50% by weight fragrance
and from about 0% to 50% active ingredients. The microsphere can
have an average sphere size in the range from about 20 microns to
about 100 microns. The nanosphere can have an average sphere size
in the range from about 0.01 micron to about 5 microns. The
nanospheres can be formed of a hydrophilic matrix material having a
melting point in the range from about 20 degrees C. to about 100
degrees C.
In the preferred embodiment, the active agent is present at a level
from about 0.01% to about 60%, preferably from about 1% to about
50% by weight of the microsphere. In the preferred embodiment, the
nanospheres are generally present in the water sensitive matrix at
a level from about 1% to about 80%, preferably from about 1% to
about 60% by weight of the matrix material with the balance being
the active agents, the cationic conditioning agent, the cationic
charge booster, and the water sensitive materials. In the preferred
embodiment, the moisture sensitive matrix is generally present at a
level from about 1% to about 80%, preferably from about 1% to about
60% by weight of the matrix material with the balance being the
active agents, the cationic conditioning agent, the cationic charge
booster, and the hydrophobic materials.
Nanospheres of the present invention can have an average diameter
in the range from about 0.01 micron to about 10 microns.
Preferably, the sphere size of the nanospheres is in the range from
about 0.05 microns to about 2 microns. It has been found that
spheres within the range of about 0.5 microns to about 1 micron are
efficiently entrained on skin surface. This linear dimension for
any individual sphere represents the length of the longest straight
line joining two points on the surface of the sphere.
Additional components can be added to the carrier system or can be
incorporated into either the nano or microsphere matrices. For
example, additional components that can be included in the carrier
system include cosmetic, dermatological, and pharmaceutical active
agents. For example, the additional components that can be added to
the controlled release system of the present invention including,
but are not limited to: anti-oxidants; free radical scavengers;
moisturizers; depigmentation agents; reflectants; humectants;
anti-microbial (e.g., antibacterial) agents; allergy inhibitors;
anti-acne agents; anti-aging agents; anti-wrinkling agents,
antiseptics; analgesics; keratolytic agents; anti-inflammatory
agents; fresheners; healing agents; anti infective; inflammation
inhibitors; wound healing promoters; peptides, polypeptides and
proteins; deodorants and antiperspirants; skin emollients and skin
moisturizers; tanning agents; skin lightening agents; anti-fungals;
depilating agents; counterirritants; poison ivy products; poison
oak products; burn products; make-up preparations; vitamins; amino
acids and their derivatives; herbal extracts; sensory markers (such
as cooling agents, heating agents, and the like); skin
conditioners; chelating agents; cell turnover enhancers; coloring
agents; sunscreens; nourishing agents; moisture absorbers; sebum
absorbers and the like; skin penetration enhancers; and other
active ingredients. The additional components are usually present
in an amount from about 1% to about 50% by weight of the
nanospheres or microspheres.
I. Cationic Charge Booster
The controlled release system of the present invention can comprise
a cationic charge booster to enhance the cationic charge density on
the nanosphere surface. Suitable cationic charge boosters are
described in U.S. Pat. No. 6,083,899 hereby incorporated by
reference into this application. The preferred cationic charge
boosters of the present invention are described herein below.
I.a. Quaternary Ammonium Compounds
A composition of the present invention comprises at least about
0.1%, preferably from about 0.1% to about 10%, more preferably from
about 0.1% to about 5% by weight, of a cationic charge booster
having the formula:
##STR00001## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are
each independently C.sub.1 C.sub.22 alkyl, C.sub.3 C.sub.22
alkenyl, R.sub.5--Q--(CH.sub.2).sub.m--, wherein R.sub.5 is C.sub.1
C.sub.22 alkyl, and mixtures thereof, m is from 1 to about 6; X is
an anion. Preferably R.sub.1 is C.sub.6 C.sub.22 alkyl, C.sub.6
C.sub.22 alkenyl, and mixtures thereof, more preferably R.sub.1
C.sub.11 C.sub.18 alkyl, C.sub.11 C.sub.18 alkenyl, and mixtures
thereof; R.sub.2, R.sub.3, and R.sub.4 are each preferably C.sub.1
C.sub.4 alkyl, more preferably each R.sub.2, R.sub.3, and R.sub.4
are methyl.
Alternatively, R.sub.1 can be a R.sub.5 --Q--(CH.sub.2).sub.m--
moiety wherein R.sub.5 is an alkyl or alkenyl moiety having from 1
to 22 carbon atoms, preferably the alkyl or alkenyl moiety when
taken together with the Q unit is an acyl unit. For example Q can
be derived from a source of triglyceride selected from tallow,
partially hydrogenated tallow, lard, partially hydrogenated lard,
vegetable oils, partially hydrogenated vegetable oils, such as
canola oil, safflower oil, peanut oil, sunflower oil, corn oil,
soybean oil, tall oil, rice bran oil, and the like and mixtures
thereof.
An example of a softener cationic booster comprising a R.sub.5
--Q--(CH.sub.2).sub.m-- moiety has the formula:
##STR00002## wherein R.sub.5 --Q-- represents oleoyl units and m is
equal to 2.
Preferably X is a softener compatible anion, such as the anion of a
strong acid. For example, X can be chloride, bromide,
methylsulfate, ethylsulfate, sulfate, nitrate and mixtures thereof.
More preferably X is chloride and methyl sulfate.
I.b. Polyvinyl Amines
A composition according to the present invention contains at least
about 0.1%, preferably from about 0.1% to about 10%, more
preferably from about 0.1% to about 5% by weight, of one or more
polyvinyl amines charge boosters having the formula:
##STR00003## wherein y is from about 3 to about 10,000, preferably
from about 10 to about 5,000, more preferably from about 20 to
about 500. Polyvinyl amines suitable for use in the present
invention are available from BASF under the name Lupasol.RTM. LU
321. The greater number of amine moieties per unit weight on the
polyvinyl amines provides preferred substantial charge density.
I.c. Polyalkyleneimines
A composition of the present invention comprises at least about
0.1%, preferably from about 0. 1% to about 10%, more preferably
from about 0. 1% to about 5% by weight, of a polyalkyleneimine
charge booster having the formula:
##STR00004## wherein the value of m is from 2 to about 700 and the
value of n is from 0 to about 350. Preferably the compounds of the
present invention comprise polyamines having a ratio of m:n that is
at least 1:1 but may include linear polymers (n equal to 0) as well
as a range as high as 10:1, preferably the ratio is 2:1. When the
ratio of m:n is 2:1, the ratio of primary:secondary:tertary amine
moieties of --RNH.sub.2, --RNH, and --RN moieties, is 1:2:1. R can
be C.sub.2 C.sub.8 alkylene, C.sub.3 C.sub.8 alkyl substituted
alkylene, and mixtures thereof. R is ethylene, 1,2-propylene,
1,3-propylene, and mixtures thereof, and preferably ethylene. R
radicals serve to connect the amine nitrogens of the backbone.
Optionally, one or more of the polyvinyl amine backbone --NH.sub.2
unit hydrogens can be substituted by an alkyleneoxy unit having the
formula: --(R.sub.1O).sub.XR.sub.2 wherein R.sub.1 is C.sub.2
C.sub.4 alkylene; R.sub.2 is hydrogen, C.sub.1 C.sub.4 alkyl, and
mixtures thereof; and x is from 1 to 50. In one embodiment of the
present invention the polyvinyl amine is reacted first with a
substrate which places a 2-propyleneoxy unit directly on the
nitrogen followed by reaction of one or more moles of ethylene
oxide to form a unit having the general formula:
##STR00005## wherein x has the value of from 1 to about 50.
Substitutions such as the above are represented by the abbreviated
formula PO--EO.sub.X--. However, more than one propyleneoxy unit
can be incorporated into the alkyleneoxy substituent.
The preferred polyamine cationic charge boosters of the present
invention comprise backbones wherein less than about 50% of the R
groups comprise more than 3 carbon atoms. The use of two and three
carbon spacers as R moieties between nitrogen atoms in the backbone
is advantageous for controlling the charge booster properties of
the molecules. More preferred embodiments of the present invention
comprise less than about 25% moieties having more than 3 carbon
atoms. Yet more preferred backbones comprise less than about 10%
moieties having more than 3 carbon atoms. Most preferred backbones
comprise about 100% ethylene moieties.
The cationic charge boosting polyamines of the present invention
comprise homogeneous or non-homogeneous polyamine backbones,
preferably homogeneous backbones. For the purpose of the present
invention the term "homogeneous polyamine backbone" is defined as a
polyamine backbone having R units that are the same such as, all
ethylene. However, this definition does not exclude polyamines that
comprise other extraneous units comprising the polymer backbone
that are present due to an artifact of the chosen method of
chemical synthesis. For example, it is known to those skilled in
the art that ethanolamine may be used as an "initiator" in the
synthesis of polyethyleneimines, therefore a sample of
polyethyleneimine that comprises one hydroxyethyl moiety resulting
from the polymerization "initiator" would be considered to comprise
a homogeneous polyamine backbone for the purposes of the present
invention.
For the purposes of the present invention the term "non-homogeneous
polymer backbone" refers to polyamine backbones that are a
composite of one or more alkylene or substituted alkylene moieties,
for example, ethylene and 1,2-propylene units taken together as R
units.
However, not all of the suitable charge booster agents belonging to
this category of polyamine comprise the above described polyamines.
Other polyamines that comprise the backbone of the compounds of the
present invention are generally polyalkyleneamines (PAAs),
polyalkyleneimines (PAIs), preferably polyethyleneamine (PEAs), or
pblyethyleneimines (PEIs). Polyethyleneimines suitable for use in
the present invention are available from BASF under the trade name
Lupasol.RTM. such as Lupasol.TM. PR8515, having an average
molecular weight of 1,800. A common polyalkyleneamine (PAA) is
tetrabutylenepentamine. PEAs can be obtained by reactions involving
ammonia and ethylene dichloride, followed by fractional
distillation. The common PEAs obtained are triethylenetetramine
(TETA) and tetraethylenepentamine (TEPA). Above the pentamines,
such as, the hexamines, heptamines, octamines and possibly
nonamines, the cogenerically derived mixture does not appear to
separate by distillation and can include other materials such as
cyclic amines and particularly piperazines.
I.d. Poly-Quaternary Ammonium Compounds
A preferred composition of the present invention comprises at least
about 0.1%, preferably from about 0.1% to about 10%, more
preferably from about 0.1% to about 5% by weight, of a cationic
charge booster having the formula:
##STR00006## wherein R is substituted or unsubstituted C.sub.2
C.sub.12 alkylene, substituted or unsubstituted C.sub.2 C.sub.12
hydroxyalkylene; each R.sub.1 is independently C.sub.1 C.sub.4
alkyl, each R.sub.2 is independently C.sub.1 C.sub.22 alkyl,
C.sub.3 C.sub.22 alkenyl, R.sub.5 --Q--(CH.sub.2).sub.m--, wherein
R.sub.5 is C.sub.1 C.sub.22 alkyl, C.sub.3 C.sub.22 alkenyl, and
mixtures thereof; m is from 1 to about 6; Q is a carbonyl unit as
described above and mixtures thereof; X is an anion.
Preferably R is ethylene and R.sub.1 is preferably methyl or ethyl,
more preferably methyl. Preferably at least one R.sub.2 is C.sub.1
C.sub.4 alkyl, more preferably methyl. Most preferably at least one
R.sub.2 is C.sub.11 C.sub.22 alkyl, C.sub.11 C.sub.22 alkenyl, and
mixtures thereof.
Alternatively R.sub.2 is a R.sub.5 --Q--(CH.sub.2).sub.m-- moiety
wherein R.sub.5 is an alkyl moiety having from 1 to 22 carbon
atoms, preferably the alkyl moiety when taken together with the Q
unit is an acyl unit derived from a source of triglyceride selected
from the group consisting of tallow, partially hydrogenated tallow,
lard, partially hydrogenated lard, vegetable oils, partially
hydrogenated vegetable oils, such as, canola oil, safflower oil,
peanut oil, sunflower oil, corn oil, soybean oil, tall oil, rice
bran oil, and the like and mixtures thereof.
An example of a cationic booster comprising a R.sub.5
--Q--(CH.sub.2).sub.m-- moiety has the formula:
##STR00007## wherein R.sub.1 is methyl, one of the R.sub.2 units is
methyl and the other of the R.sub.2 unit is R.sub.5
--Q--(CH.sub.2).sub.m-- wherein R.sub.5 --Q-- is an oleoyl unit and
m is equal to 2. X is a softener compatible anion, such as an anion
of a strong acid. For example, X can be chloride, bromide,
methylsulfate, ethylsulfate, sulfate, nitrate and mixtures thereof.
More preferably chloride and methyl sulfate. II. Cationic
Conditioning Agents
The nanospheres of the present invention can comprise any of the
cationic conditioning agents known in the art.
Hydrocarbon conditioners suitable for use herein are selected from
the following classes of compounds:
(i) Cationic quaternary ammonium salts. The counterion is methyl
sulfate or any alkyl sulfate or any halide. Examples of cationic
quaternary ammonium salts include, but are not limited to: (1)
Acyclic quaternary ammonium salts having at least two C.sub.8-30,
preferably C.sub.12-22 alkyl chains, such as: ditallowdimethyl
ammonium methylsulfate, di(hydrogenated tallow)dimethyl ammonium
methylsulfate, distearyldimethyl ammonium methylsulfate,
dicocodimethyl ammonium methylsulfate and the like; (2) Cyclic
quaternary ammonium salts of the imidazolinium type such as
di(hydrogenated tallow)dimethyl imidazolinium methylsulfate,
1-ethylene-bis(2-tallow-1-methyl) imidazolinium methylsulfate and
the like; (3) Diamido quaternary ammonium salts such as:
methyl-bis(hydrogenated tallow amidoethyl)-2-hydroxyethyl ammonium
methyl sulfate, methyl bis(tallowamidoethyl)-2-hydroxypropyl
ammonium methylsulfate and the like; (4) Biodegradable quaternary
ammonium salts such as N,N-di (tallowoyl-oxy-ethyl)-N,N,-dimethyl
ammonium methyl sulfate and N,N-di
(tallowoyl-oxy-propyl)-N,N-dimethyl ammonium methyl sulfate.
Biodegradable quaternary ammonium salts are described, for example,
in U.S. Pat. Nos. 4,137,180, 4,767,547 and 4,789,491 incorporated
herein by reference.
Preferred biodegradable quaternary ammonium salts include the
biodegradable cationic diester compounds (See U.S. Pat. No.
4,137,180, incorporated herein by reference).
(ii) Tertiary fatty amines having at least one and preferably two
C.sub.8 to C.sub.30, preferably C.sub.12 to C.sub.22 alkyl chains.
Examples include hardened tallow-di-methylamine and cyclic amines
such as 1-(hydrogenated tallow)amidoethyl-2-(hydrogenated
tallow)imidazoline. Cyclic amines which may be employed for the
compositions herein are described in U.S. Pat. No. 4,806,255
incorporated herein by reference.
(iii) Carboxylic acids having 8 to 30 carbons atoms and one
carboxylic group per molecule. The alkyl portion has 8 to 30,
preferably 12 to 22 carbon atoms. The alkyl portion may be linear
or branched, saturated or unsaturated, with linear saturated alkyl
preferred. Stearic acid is a preferred fatty acid for use in the
composition herein. Examples of these carboxylic acids are
commercial grades of stearic acid and palmitic acid, and mixtures
thereof which may contain small amounts of other acids.
(iv) Esters of polyhydric alcohols such as sorbitan esters or
glycerol stearate. Sorbitan esters are the condensation products of
sorbitol or iso-sorbitol with fatty acids such as stearic acid.
Preferred sorbitan esters are monoalkyl. A common example of
sorbitan ester is SPAN 60 (ICI) which is a mixture of sorbitan and
isosorbide stearates.
(v) Fatty alcohols, ethoxylated fatty alcohols, alkylphenols,
ethoxylated alkylphenols, ethoxylated fatty amines, ethoxylated
monoglycerides and ethoxylated diglycerides.
(vi) Mineral oils, and polyols such as polyethylene glycol.
(vi) Silicone oils and silicone surfactants as described in Lin et
al., U.S. Pat. No. 5,174,911 and Lin et al. U.S. patent application
Ser. No. 07/776,719, incorporated herein by reference.
These softeners are more definitively described in U.S. Pat. No.
4,134,838 the disclosure of which is incorporated by reference
herein.
Other quaternary ammonium salt conditioning compounds suitable for
use are disclosed by Morton D. R. et al. in U.S. Pat. Nos.
3,686,025 and 6,083,899 are described in "Cationic Surfactants",
Surfactant Science series, Vol. 34, edited by Richmond J. M.,
Marcel Dekker Inc., 1990, which are incorporated herein by
reference.
The particularly preferred cationic conditioning agents for the
carrier of the present invention are: behenyltrimethylammonium
chloride; ditallowdimethylammonium methylsulfate;
ditallowdimethylammonium chloride; methyl(1) stearylamidoethyl (2)
stearylimidazolinium methosulfate;
methyl(1)stearylamidoethyl(2)stearylimidazolinium chloride;
N,N-di(tallowyl-oxy-ethyl)-N,N-dimethyl ammonium chloride;
N,N-di(canolyl-oxy-ethyl)-N,N-dimethyl ammonium chloride;
N,N-di(tallowyl-oxy-ethyl)-N-methyl, N-(2-hydroxyethyl) ammonium
chloride; N,N-di(canolyl-oxy-ethyl)-N-methyl, N-(2-hydroxyethyl)
ammonium chloride; N,N-di(2-tallowyloxy-2-oxo-ethyl)-N,N-dimethyl
ammonium chloride; N,N-di(2-canolyloxy-2-oxo-ethyl)-N,N-dimethyl
ammonium chloride;
N,N-di(2-tallowyloxyethylcarbonyloxyethyl)-N,N-dimethyl ammonium
chloride; N,N-di(2-canolyloxyethylcarbonyloxyethyl)-N,N-dimethyl
ammonium chloride;
N-(2-tallowoyloxy-2-ethyl)-N-(2-tallowyloxy-2-oxo-ethyl)-N,N-dimethyl
ammonium chloride;
N-(2-canolyloxy-2-ethyl)-N-(2-canolyloxy-2-oxo-ethyl)-N,N-dimethyl
ammonium chloride; N,N,N-tri(tallowyl-oxy-ethyl)-N-methyl ammonium
chloride; N,N,N-tricanolyl-oxy-ethyl)-N-methyl ammonium chloride;
N-(2-tallowyloxy-2-oxoethyl)-N-(tallowyl)-N,N-dimethyl ammonium
chloride; N-(2-canolyloxy-2-oxoethyl)-N-(canolyl)-N,N-dimethyl
ammonium chloride;
1,2-ditallowyloxy-3-N,N,N-trimethylammoniopropane chloride; and
1,2-dicanolyloxy-3-N,N,N-trimethylammoniopropane chloride; and
mixtures of thereof.
Methyl-1-tallowamidoethyl-2-tallowimidazolinium methylsulfate
available from Witco Chemical Company under the name Varisoft.TM.
475. Examples of monoalkyltrimethylammonium salts are
monotallowtrimethylammonium chloride, mono(hydrogenated
tallow)trimethylammonium chloride, palmityltrimethyl ammonium
chloride and soyatrimethylammonium chloride, available from Witco
Chemical Company under the names Adogen.TM. 471, Adogen.TM. 441,
Adogen.TM. 444, and Adogen.TM. 415, respectively. Examples of
behenyltrimethylammonium chloride are commercially available under
the name Kemamine.TM. Q2803-C from Humko Chemical Division of Witco
Chemical Corporation.
Methylbis(tallowamidoethyl)(2-hydroxyethyl)ammonium methylsulfate
and methylbis(hydrogenated
tallowamidoethyl)(2-hydroxyethyl)ammonium methylsulfate; are
available from Witco Chemical Company under the names Varisof.TM.
222 and Varisoft.TM. 110, respectively: dimethylstearylbenzyl
ammonium chloride sold under the names Varisoft.TM. SDC by Witco
Chemical Company and Ammonyx.TM. 490 by Onyx Chemical Company.
The most preferred cationic surface-active agents are cetyl
trimethylammonium chloride and behenamidopropyl hydroxyethyl
dimonium chloride under the name Incroquat Behenyl HE.RTM.,
commercially available from Croda Inc.
In one embodiment of the present invention the nanosphere matrix is
the cationic conditioning agent.
III. Matrix Materials for Forming the Nanospheres
Suitable solid core materials for forming nanospheres of the
present invention are inert nontoxic hydrophobic materials with a
melting point range between about 20 degrees C. and about 90
degrees C. Examples of hydrophobic materials include natural,
regenerated, or synthetic waxes including animal waxes such as
beeswax, lanolin and shellac wax, vegetable waxes such as camauba,
candelilla, sugar cane, rice bran, and bayberry wax, mineral waxes
such as petroleum waxes including paraffin and microcrystalline
wax, and mixtures thereof. Other hydrophobic materials which can be
used in the present invention include wax and silicon copolymers,
such as candelilla wax and silicone copolymer, ozokrite wax and
silicon copolymers, beeswax and silicon copolymers, and the like.
Other hydrophobic compounds which can be used in the present
invention include: fatty acid esters such as ethyl stearate,
isopropyl myristate, and isopropyl palmitate; high molecular weight
fatty alcohols such as cetostearyl alcohol, cetyl alcohol, stearyl
alcohol, and oleyl alcohol, solid hydrogenated castor and vegetable
oils, hard paraffins, hard fats, and mixtures thereof. Other
hydrophobic compounds which can be used, include triglycerides,
preferably of at least food grade purity, which can be produced by
synthesis or by isolation from natural sources. Natural sources can
include animal fat or vegetable oil, such as soy oil, as a source
of long chain triglycerides (LCT). Other triglycerides suitable for
use in the present invention are composed of a majority of medium
length fatty acids (C10 C18), denoted medium chain triglycerides
(MCT). The fatty acid moieties of such triglycerides can be
unsaturated or polyunsaturated and mixtures of triglycerides having
various fatty acid material. The nanosphere matrix can comprise a
single hydrophobic material or a mixture of a plurality of
materials. Other hydrophobic materials that are known to those
skilled in the art and suitable materials as described in
"Industrial Waxes," Vol. I and II, by Bennett F. A. I. C.,
published by Chemical Publishing Company Inc., 1975 and Martindale,
"The Extra Pharmacopoeia", The Pharmaceutical Press, 28.sup.th
Edition pp. 1063 1072, 1982 can be used in the present
invention.
Other hydrophobic compounds which can be used in the present
invention include synthetic polymers, such as alkylated
polyvinylpyrrolidines, the Ganex.RTM. copolymer series, and
ProLipids.RTM. 151 (commercially available from the ISP Company),
Purester.RTM. series of materials (especially Purester.RTM. 24 and
Purester.RTM. 34, vegetable derived esters produced from naturally
derived fatty alcohol & methyl ester feedstocks which are
non-GMO vegetable based renewable resources, commercially available
from Strahl & Pitsch Inc. of West Babylon, N.Y.).
Examples of other suitable hydrophobic polymers and copolymer for
use as the matrix material include polyethylene homopolymers
A-C.RTM. 1702; A-C.RTM. 617, A-C.RTM. 617A, and A-C.RTM. 15,
commercially available from Allied Signal Inc.; PERFORMALENE.TM.
polyethylene homopolymer series commercially available from New
Phase Technologies; PERFORMACOL.TM. linear primary alcohols series
commercially available from New Phase Technologies; PERFORMACID.TM.
linear saturated carboxylic acid series commercially available from
New Phase Technologies; PERFORMA V.TM. polymer series commercially
available from New Phase Technologies; ETHYLENE-ACRYLIC ACID
COPOLYMERS A-C.RTM. 540, A-C.RTM. 540A, and A-C.RTM. 580
commercially available from Allied Signal Inc.; polyamides having a
molecular weight in the range of from about 6,000 up to about
12,000, for example, MACROMELT.TM. 6030 manufactured by the Henkel
Ag. of Dusseldorf, Germany; VERSALON.TM. 1135 polyamide polymer
available commercially from General Mills, Inc
It is preferred that the nanospheres of the present invention have
a melting point in the range from about 20 degrees C. to about 90
degrees C., preferably from about 40 degrees C. to about 90 degrees
C. The melting point of the spheres is usually a function of the
carrier matrix employed. Accordingly, preferred matrix materials
have a melting point in the range of about 50 degrees C. to about
80 degrees C., preferably from about 60 degrees C. to about 70
degrees C. It should be understood that it is the melting point of
the sphere rather than of the carrier matrix that is important for
use of the carrier system of the present invention.
Considerations in the selection of the matrix material include good
barrier properties to the active agents and the fragrance
ingredients, low toxicity and irritancy, stability, and high
loading capacity for the active agents of interest.
IV. Matrix Materials for Forming a Microsphere Matrix
Water-sensitive materials for forming the microspheres of the
present invention comprises of polyvinyl pyrrolidone, water soluble
cellulose, polyvinyl alcohol, ethylene maleic anhydride copolymer,
methyl vinyl ether maleic anhydride copolymer, polyethylene oxide,
water soluble polyamide or polyester, copolymers or homopolymers of
acrylic acid such as polyacrylic acid, polystyrene acrylic acid
copolymers or starch derivatives, polysaccharide, hydrocolloid,
natural gum, protein, and mixtures thereof.
Examples of synthetic water sensitive polymers which are useful for
the invention include polyvinyl pyrrolidone, water soluble
celluloses, polyvinyl alcohol, ethylene maleic anhydride copolymer,
methylvinyl ether maleic anhydride copolymer, acrylic acid
copolymers, anionic polymers of methacrylic acid and methacrylate,
cationic polymers with dimethyl-aminoethyl ammonium functional
groups, polyethylene oxides, water soluble polyamide or
polyester.
Examples of water soluble hydroxyalkyl and carboxyalkyl celluloses
include hydroxyethyl and carboxymethyl cellulose, hydroxyethyl and
carboxyethyl cellulose, hydroxymethyl and carboxymethyl cellulose,
hydroxypropyl carboxymethyl cellulose, hydroxypropyl methyl
carboxyethyl cellulose, hydroxypropyl carboxypropyl cellulose,
hydroxybutyl carboxymethyl cellulose, and the like. Also useful are
alkali metal salts of these carboxyalkyl celluloses, particularly
and preferably the sodium and potassium derivatives.
The polyvinyl alcohol useful in the practice of the invention is
partially and fully hydrolyzed polyvinyl acetate, termed "polyvinyl
alcohol" with polyvinyl acetate as hydrolyzed to an extent, also
termed degree of hydrolysis, of from about 75% up to about 99%.
Such materials are prepared by means of any of Examples I XIV of
U.S. Pat. No. 5,051,222 issued on Sep. 24, 1991, the specification
for which is incorporated by reference herein.
Polyvinyl alcohol useful for practice of the present invention is
Mowiol.RTM. 3-83, having a molecular weight of about 14,000 Da and
degree of hydrolysis of about 83%, Mowiol.RTM. 3-98 and a fully
hydrolyzed (98%) polyvinyl alcohol having a molecular weight of
16,000 Da commercially available from Gehring-Montgomery, Inc. of
Warminister Pa. Other suitable polyvinyl alcohols are: AIRVOL.RTM.
205, having a molecular weight of about 15,000 27,000 Da and degree
of hydrolysis of about 88%, and VINEX.RTM. 1025, having molecular
weight of 15,000 27,000 Da degree of hydrolysis of about 99% and
commercially available from Air Products & Chemicals, Inc. of
Allentown, Pa.; ELVANOL.RTM. 51-05, having a molecular weight of
about 22,000 26,000 Da and degree of hydrolysis of about 89% and
commercially available from the Du Pont Company, Polymer Products
Department, Wilmington, Del.; ALCOTEX.RTM. 78 having a degree of
hydrolysis of about 76% to about 79%, ALCOTEX.RTM. F88/4 having a
degree of hydrolysis of about 86% to about 88% and commercially
available from the Harlow Chemical Co. Ltd. of Templefields,
Harlow, Essex, England CM20 2BH; and GOHSENOL.RTM. GL-03 and
GOHSENOL.RTM. KA-20 commercially available from Nippon Gohsei K.
K., The Nippon Synthetic Chemical Industry Co., Ltd., of No. 9-6,
Nozaki Cho, Kita-Ku, Osaka, 530 Japan.
Suitable polysaccharides are polysaccharides of the non-sweet,
coloidally-soluble types, such as natural gums, for example, gum
arabic, starch derivates, dextrinized and hydrolyzed starches, and
the like. A suitable polysaccharide is a water dispersible,
modified starch commercially available as Capule.RTM., N-Lok.RTM.,
Hi-Cap.TM. 100 or Hi-Cap.TM. 200 commercially available from the
National Starch and Chemical Company of Bridgewater, N.J.;
Pure-Cote.TM., commercially available from the Grain Processing
Corporation of Muscatine, Iowa. In the preferred embodiment the
natural gum is a gum arabic, commercially available from TIC Gums
Inc., Belcamp, Midland. Suitable hydrocolloids are xanthan,
maltodextrin, galactomanan or tragacanth, preferably maltodextrins
such as Maltrinm.TM. M100, and Maltrin.TM. M150, commercially
available from the Grain Processing Corporation of Muscatine,
Iowa.
V. Active Ingredients
Vitamins
Various vitamins can be included in the controlled release system
of the present invention. For example, vitamin A and derivatives
thereof, vitamin B.sub.2, biotin, pantothenic acid, vitamin K,
vitamin D, vitamin E and mixtures thereof can be used.
Antimicrobial and Antifungal Actives
Antimicrobial and antifungal actives can be included in the
controlled release system of the present invention. Antimicrobial
and antifungal actives can be effective to prevent the
proliferation and growth of bacteria and fungi and can be used in
the controlled release system for stabilizing retinol of the
present invention. Non-limiting examples of antimicrobial and
antifungal actives include beta-lactam drugs, quinolone drugs,
ciprofloxacin, norfloxacin, tetracycline, erythromycin, amikacin,
2,4,4'-trichloro-2'-hydroxy diphenyl ether,
3,4,4'-trichlorobanilide, phenoxyethanol, phenoxy propanol,
phenoxyisopropanol, doxycycline, capreomycin, chlorhexidine,
chlortetracycline, oxytetracycline, clindamycin, ethambutol,
hexamidine isethionate, metronidazole, pentamidine, gentamicin,
kanamycin, lineomycin, methacycline, methenamine, minocycline,
neomycin, netilmicin, paromomycin, streptomycin, tobramycin,
miconazole, tetracycline hydrochloride, erythromycin, zinc
erythromycin, erythromycin estolate, erythromycin stearate,
amikacin sulfate, doxycycline hydrochloride, capreomycin sulfate,
chlorhexidine gluconate, chlorhexidine hydrochloride,
chlortetracycline hydrochloride, oxytetracycline hydrochloride,
clindamycin hydrochloride, ethambutol hydrochloride, metronidazole
hydrochloride, pentamidine hydrochloride, gentamicin sulfate,
kanamycin sulfate, lineomycin hydrochloride, methacycline
hydrochloride, methenamine hippurate, methenamine mandelate,
minocycline hydrochloride, neomycin sulfate, netilmicin sulfate,
paromomycin sulfate, streptomycin sulfate, tobramycin sulfate,
miconazole hydrochloride, amanfadine hydrochloride, amanfadine
sulfate, octopirox, parachlorometa xylenol, nystatin, tolnaftate,
zinc pyrithione; clotrimazole; alantolactone; isoalantolactone;
alkanet extract (alaninin); anise; arnica extract (helenalin
acetate and 11, 13 dihydrohelenalin); Aspidium extract (phloro,
lucinol containing extract); barberry extract (berberine chloride);
bay sweet extract; bayberry bark extract (myricitrin); benzalkonium
chloride; benzethonium chloride; benzoic acid and its salts;
benzoin; benzyl alcohol; blessed thistle; bletilla tuber;
bloodroot; bois de rose oil; burdock; butyl paraben; cade oil; CAE
(available from Ajinomoto, located in Teaneck, N.J.); cajeput oil;
Cangzhu; capsicum frutescens extract; caraway oil; cascarilla bark
(sold under the tradename ESSENTIAL OIL); cedarleaf oil;
chamomille; chaparral; chlorhexidine gluconate; chlorophenesin;
chlorxylenol; cinnamon oil; citronella oil; clove oil; Crinipan AD
(available from Climbazole); 2,3-dihydro-farnesol; dehydroacetic
acid and its salts; dill seed oil; DOWICIL 200 (available from Dow
Chemical, located in Midland, Mich.); echinacea; elenolic acid;
epimedium; ethyl paraben; Fo-Ti; galbanum; garden bumet; GERMALL
115 and GERMALL II (available from ISP-Sutton Labs, located in
Wayne, N.J.); German chamomile oil; giant knotweed; GLYDANT
(available from Lonza, located in Fairlawn, N.J.); GLYDANT PLUS
(available from Lonza); grapefruit seed oil; 1,6 hexanediol;
hexamidine diisethionate; hinokitiol; honey; honeysuckle flower;
hops; immortelle; iodopropynl butyl carbamide (available from
Lonza); isobutyl paraben; isopropyl paraben; JM ACTICARE (available
from Microbial Systems International, located in Nottingham, NG);
juniper berries; KATHON CG (available from Rohm and Haas, located
in Philadelphia, Pa.); kojic acid; labdanum; lavender; lemon balm
oil; lemon grass; methyl paraben; mint; mume; mustard; myrrh; neem
seed oil; ortho phenyl phenol; olive leaf extract (available from
Bio Botanica); parsley; patchouly oil; peony root; 1,2 pentandiol;
PHENONIP (available from Nipa Labs, located in Wilmington, Del.);
phenoxyethanol; phytosphingosine; pine needle oil; PLANSERVATIVE
(available from Campo Research); propyl paraben; purslane;
quillaira; rhubarb; rose geranium oil; rosemary; sage; salicylic
acid; sassafras; savory; sichuan lovage; sodium meta bisulfite;
sodium sulfite; SOPHOLIANCE (available from Soliance, located in
Compiegne, France); sorbic acid and its salts; sphingosine; stevia;
storax; sucrose esters; tarmic acid; tea; tea tree oil (cajeput
oil); thyme; triclosan; triclocarban; tropolone; turpentine;
umbelliferone (antifungal); yucca; and mixtures thereof.
Anti-inflammatory Agents
Anti-inflammatories can be included in the controlled release
system of the present invention to enhance photoprotection
benefits, particularly from UVA. Suitable steroidal
anti-inflammatories include hydrocortisone; non-steroidal
anti-inflammatories such as oxicans, salicylates, acetic acid
derivatives, fenamates, propionic acid derivatives, pyrazoles,
substituted phenyl compounds, 2-naphthyl containing compounds, and
natural anti-inflammatories such as aloe vera. Examples of
anti-inflammatories are described in U.S. Pat. No. 5,487,884, the
entire contents of which are incorporated herein by reference.
Anti-Acne Agents
Anti-acne agents can be included in the controlled release system
of the present invention. Non-limiting examples of useful anti-acne
actives include the keratolytics such as salicylic acid
(o-hydroxybenzoic acid), derivatives of salicylic acid such as
5-octanoyl salicylic acid and 4 methoxysalicylic acid, and
resorcinol; retinoids such as retinoic acid and its derivatives
(e.g., cis and trans); sulfur-containing D and L amino acids and
their derivatives and salts, particularly their N-acetyl
derivatives, a preferred example of which is N-acetyl-L-cysteine;
lipoic acid; antibiotics and antimicrobials such as benzoyl
peroxide, octopirox, tetracycline, 2,4,4'-trichloro-2'-hydroxy
diphenyl ether, 3,4,4'-trichlorobanilide, azelaic acid and its
derivatives, phenoxyethanol, phenoxypropanol, phenoxyisopropanol,
ethyl acetate, clindamycin and meclocycline; sebostats such as
flavonoids and bioflavonoids; bile salts such as symbol sulfate and
its derivatives, deoxycholate, and cholate; abietic acid;
adapalene; allantoin; aloe extracts; arbietic acid and its salts;
aryl-2,4 dioxo oxazolidine derivatives; ASEBIOL (available from
Laboratories Serobiologiques, located in Somerville, N.J.); azaleic
acid; barberry extracts; bearberry extracts; belamcanda chinensis;
benzoquinolinones; benzoyl peroxide; berberine; BIODERMINE
(available from Sederma, located in Brooklyn, N.Y.); bioflavinoids;
bisabolol; S-carboxymethyl cysteine; carrot extracts; cassin oil;
clove extracts; citral; citronellal; climazole; Completech MBAC-OS
(available from Lipo); CREMOGEN M82 (available from Dragoco,
located in Totowa, N.J.); cucumber extracts; dehydroacetic acid and
its salts; dehydroeplandersterone salicylate; dichlorophenyl
imidazoldioxolan which is commercially available as COMPLETECH
MBAC-OS (from Lipo, located in Paterson, N.J.); DL valine and its
esters; DMDM hydantoin; Epicutin TT (available from CLR);
erythromycin; escinol; ethyl hexyl monoglyceryl ether; ethyl
2-hydroxy undecanoate; farnesol; farnesol acetate; geranoil;
glabridin; gluconic acid; gluconolactone; glyceryl monocaprate;
glycolic acid; grapefruit seed extract; gugu lipid; Hederagenin
(available from Maruzen); hesperitin; hinokitol; hops extract;
hydrogenated rosin; 10 hydroxy decanoic acid; ichtyhol; interleukin
1 alpha antagonists; iodo-2-propynyl butyl carbamate; Kapilarine
(available from Greentech); ketoconazole; lactic acid; lemon grass
oil; Lichochalcone LR15 (available from Maruzen); linoleic acid;
LIPACIDE C8CO (available from Seppic, located in Paris, France);
lovastatin; 4 methoxysalicylic acid; metronidazole; minocycline;
mukurossi; neem seed oil; vitamin B.sub.3 compounds (such as
niacinamide and nicotinic acid); nisin; 5-octanoly salicylic acid;
octopirox; panthenol; 1-pentadecanol; peonia extract; peppermint
extract; phelladendron extract; 2-phenyl-benzothiophene
derivatives; phloretin; PHLOROGINE (available from Secma);
phosphatidyl choline; proteolytic enzymes; quercetin; red
sandalwood extract; resorcinol; rosemary extract; rutin; sage
extract; salicin; salicylic acid; skull cap extract; siber hegner
extract; siberian saxifrage extract; silicol; sodium lauryl
sulfate; sodium sulfoacetamide; Sophora Extract (available from
Maruzen); sorbic acid; sulfur; sunder vati extract; tea tree oil;
tetracyline; tetra hydroabietic acid; thyme extract; tioxolone;
tocopherol; trehalose 6-undecylenoate; 3 tridecene-2-ol; triclosan;
tropolone; UNITRIENOL T27 (available from Unichem, located in
Gouda, Netherlands); vitamin D.sub.3 and its analogs; white thyme
oil; willow bark extract; wogonin; Ylang Ylang; zinc glycerolate;
zinc linoleate; zinc oxide; zinc pyrithione; zinc sulfate and
mixtures thereof.
Non-steroidal Cosmetic Soothing Actives
Cosmetic actives can be included in the controlled release system
of the present invention. Cosmetic soothing actives can be
effective in preventing or treating inflammation of the skin and
can be included in the controlled release system of the present
invention. The soothing active enhances the skin appearance
benefits of the present invention, e.g., such agents contribute to
a more uniform and acceptable skin tone or color. The exact amount
of anti-inflammatory agent to be used in the compositions will
depend on the particular anti-inflammatory agent utilized since
such agents vary widely in potency. Non-limiting examples of
cosmetic soothing agents include the following categories:
propionic acid derivatives; acetic acid derivatives; fenamic acid
derivatives; biphenylcarboxylic acid derivatives; and oxicams. All
of these cosmetic soothing actives are fully described in U.S. Pat.
No. 4,985,459 to Sunshine et al., issued Jan. 15, 1991,
incorporated by reference herein in its entirety. Non-limiting
examples of useful cosmetic soothing actives include acetyl
salicylic acid, ibuprofen, naproxen, benoxaprofen, flurbiprofen,
fenoprofen, fenbufen, ketoprofen, indoprofen, pirprofen, carprofen,
oxaprozin, pranoprofen, miroprofen, tioxaprofen, suprofen,
alminoprofen, tiaprofenic acid, fluprofen, bucloxic acid,
absinthium, acacia, aescin, alder buckthorn extract, allantoin,
aloe, APT (available from Centerchem), amica, astragalus,
astragalus root extract, azulene, Baicalin SR 15 (available from
Barnet Products Dist.), baikal skullcap, baizhu, balsam canada, bee
pollen, BIOPHYTEX (available from Laboratories Serobiologiques),
bisabolol, black cohosh, black cohosh extract blue cohosh, blue
cohosh extract, boneset, borage, borage oil, bradykinin
antagonists, bromelain, calendula, calendula extract, Canadian
Willowbark Extract (available from Fytokem), candelilla wax,
Cangzhu, canola phytosterols, capsicum, carboxypeptidase, celery
seed, celery stem extract, CENTAURIUM (available from Sederma),
centaury extract, chamazulene, chamomile, chamomile extract,
chaparral, chaste tree, chaste tree extract, chickweed, chicory
root, chicory root extract, chirata, chishao, collodial oatmeal,
comfrey, comfrey extract, CROMOIST CM GLUCAN (available from
Croda), darutoside, dehurian angelica, devil's claw, divalent
metals (such as, magnesium, strontium, and manganese), doggrass,
dogwood, Eashave (available from Pentapharm), eleuthero, ELHIBIN
(available from Pentapharm), ENTELINE 2 (available from Secma),
ephedra, epimedium, esculoside; ethacrynic acid, evening primrose,
eyebright, Extract LE-100 (available from Sino Lion), Fangfeng,
feverfew, ficin, forsythia fruit, Fytosterol 85 (available from
Fytokem), ganoderma, gaoben, Gatuline A (available from
Gattefosse), gentian, germanium extract, gingko bilboa extract,
ginkgo, ginseng extract, goldenseal, gorgonian extract, gotu kola,
grape fruit extract, guaiac wood oil, guggal extract, helenalin
esters, henna, honeysuckle flower, horehound extract,
horsechestnut, horsetail, huzhang, hypericum, ichthyol, immortelle,
ipecac, job's tears, jujube, kola extract, LANACHRYS 28 (available
from Lana Tech), lemon oil, lianqiao, licorice root, ligusticum,
ligustrum, lovage root, luffa, mace, magnolia flower, manjistha
extract, margaspidin, matricin, melatonin, MICROAT IRC (available
from Nurture), mints, mistletoe, Modulene (available from Seporga),
mono or diglucosides of glabridin, mono or diglucosides of
gentisin, MTA (5'-deoxy-5'-methythioadenosine), mung bean extract,
musk, N-methyl arginine, oat beta glucan, oat extract, orange,
panthenol, papain, phenoxyacetic acid, peony bark, peony root,
Phytoplenolin (available from Bio Botanica), phytosphingosine,
Preregen (available from Pentapharm), purslane, QUENCH T (available
from Centerchem), quillaia, red sage, rehmannia, rhubarb, rosemary,
rosmarinic acid, royal jelly, rue, rutin, sandlewood, sanqi,
sarsaparilla, saw palmetto, SENSILINE (available from Silab),
SIEGESBECKIA (available from Sederma), stearyl glycyrrhetinate,
Stimutex (available from Pentapharm), storax, strontium nitrate,
sweet birch oil, sweet woodruff, tagetes, tea extract, thyme
extract, tienchi ginseng, tocopherol, tocopheryl acetate,
triclosan, turmeric, urimei, ursolic acid, white pine bark, witch
hazel xinyi, yarrow, yeast extract, yucca, and mixtures
thereof.
Skin Lightening Actives
Skin lightening actives can be included in the controlled release
system of the present invention. Skin lightening actives can
actually decrease the amount of melanin in the skin or provide such
an effect by other mechanisms and can be included in the controlled
release system for stabilizing retinol of the present invention.
Skin lightening actives suitable for use herein are described in
co-pending patent application U.S. patent application Ser. No.
08/479,935, filed on Jun. 7, 1995 in the name of Hillebrand,
corresponding to PCT Application No. U.S. Ser. No. 95/07432, filed
Jun. 12, 1995; and copending patent application U.S. patent
application Ser. No. 08/390,152, filed on Feb. 24, 1995 in the
names of Kalla L. Kvalnes, Mitchell A. DeLong, Barton J. Bradbury,
Curtis B. Motley, and John D. Carter, corresponding to PCT
Application No. U.S. Ser. No. 95/02809, filed Mar. 1, 1995,
published Sep. 8, 1995; all incorporated herein by reference.
Non-limiting examples of skin lightening actives useful herein
include adapalene, aloe extract, alpha-glycaryl-L-ascorbic acid,
aminotyroxine, ammonium lactate, anethole derivatives, apple
extract, arbutin, areca catechu L. extract, ascorbic acid, ascorbyl
palmitate, azelaic acid, bamboo extract, bearberry extract,
bletilla tuber, bupleurum falcatum extract, burnet extract, Burnet
Power (available from Barnet Products), butyl hydroxy anisole,
butyl hydroxy toluene, butyl resoreinol, Chuanxiong, cola decaballo
extract, Dang-Gui, deoxyarbutin, 1,3 diphenyl propane derivatives,
2,5 dihydroxybenzoic acid and its derivatives,
2-(4-acetoxyphenyl)-1,3 dithane, 2-(4-hydroxyphenyl)-1,3 dithane,
ellagic acid, escinol, estragole derivatives, esculoside,
esculetin, FADEOUT (available from Pentapharm), Fangfeng, fennel
extract, gallic acid and its derivatives, ganodenna extract,
gaoben, GATULINE WHITENING (available from Gattlefosse), genistic
acid and its derivatives, gentisyl alcohol, glabridin and its
derivatives, gluco pyranosyl-1-ascorbate, gluconic acid,
glucosamine, glycolic acid, glycyrrhizinic acid, green tea extract,
4-Hydroxy-5-methyl-3[2H]-furanone, hydroquinine, 4 hydroxyanisole
and its derivatives, 4-hydroxy benzoic acid derivatives,
hydroxycaprylic acid, hyptis extract, inositol ascorbate, kojic
acid, kojic dipalnitate, lactic acid, lemon extract, licorice
extract, Licorice P-TH (available from Barnet Products), linoleic
acid, magnesium ascorbyl phosphate, Melfade (available from
Pentapharm), MELAWHITE (available from Pentapharm), Melanostatine
DM (available from Laboratories Seporga), morus alba extract,
mulberry root extract, niacinamide, 5-octanoyl salicylic acid,
parsley extract, phellinus linteus extract, pinon blanco extract,
pinon negro extract, piri-piri extract, pyrogallol derivatives,
retinoic acid, retinol, retinyl esters (acetate, propionate,
palmitate, linoleate), 2,4 resorcinol derivatives, 3,5 resorcinol
derivatives, rose fruit extract, rucinol, salicylic acid, Song-Yi
extract, Sophora Powder (available from Barnet Products),
4-thioresorein, 3,4,5 trihydroxybenzyl derivatives, tranexamic
acid, tyrostat (Rumex Extract available from Fytokem), Tyroslat
10,11 (available from Fytokem), vanilla derivatives, vitamin
D.sub.3 and its analogs, and mixtures thereof.
Sunscreen Actives
Sun screen agents can be included in the controlled release system
of the present invention. The term "sunscreen agent" as used herein
defines ultraviolet ray-blocking compounds exhibiting absorption
within the wavelength region between about 290 and about 400 nm.
Sunscreens can be classified into five groups based upon their
chemical structure: para-amino benzoates; salicylates; cinnamates;
benzophenones; and miscellaneous chemicals including menthyl
anthranilate and digalloyl trioleate. Inorganic sunscreens can also
be used including titanium dioxide, zinc oxide, iron oxide and
polymer particles such as those of polyethylene,
polymethylmethacrylates and polyamides.
A wide variety of conventional sunscreening agents are suitable for
use in the present invention as described in Segarin et al., at
Chapter VIII, Pages 189 et seq., "Cosmetics Science and
Technology", the disclosure of which is incorporated herein by
reference. Specific suitable sunscreening agents include, for
example: p-aminobenzoic acid, its salts and derivatives,
anthranilates, salicylates, cinnamic acid derivatives,
dihydroxycinnamic acid derivatives, trihydroxycinnamic acid
derivatives, hydrocarbons, dibenzalacetone and benzalacetophenone,
naphthosulfonates, dihydroxy-naphthoic acid and its salts, o- and
p-hydroxy-biphenyldisulfonates, coumarin derivatives, diazoles
quinine salts, quinoline derivatives, hydroxy or methoxy
substituted benzophenones, uric and vilouric acids, tannic acid and
its derivatives, hydroquinone, benzophenones, and the like.
Also useful herein are sunscreening actives. A wide variety of
sunscreening agents are described in U.S. Pat. No. 5,087,445, to
Haffey et al., issued Feb. 11, 1992; U.S. Pat. No. 5,073,372, to
Turner et al., issued Dec. 17, 1991; U.S. Pat. No. 5,073,371, to
Turner et al. issued Dec. 17, 1991; and Segarin, et al., at Chapter
VIII, pages 189 et seq., of Cosmetics Science and Technology, all
of which are incorporated herein by reference in their entirety.
Non-limiting examples of sunscreens which are useful in the
compositions of the present invention are those selected from the
group consisting of 2-ethylhexyl p-methoxycinnamate, 2-ethylhexyl
N,N-dimethyl-p-aminobenzoate, p-aminobenzoic acid,
2-phenylbenzimidazole-5-sulfonic acid, octocrylene, oxybenzone,
homomenthyl salicylate, octyl salicylate,
4,4'-methoxy-t-butyldibenzoylmethane, 4-isopropyl dibenzoylmethane,
3-benzylidene camphor, 3-(4-methylbenzylidene) camphor, titanium
dioxide, zinc oxide, silica, iron oxide, and mixtures thereof.
Still other useful sunscreens are those disclosed in U.S. Pat. No.
4,937,370, to Sabatelli, issued Jun. 26, 1990; and U.S. Pat. No.
4,999,186, to Sabatelli et al., issued Mar. 12, 1991; these two
references are incorporated by reference herein in their entirety.
Still other useful sunscreens include aminobenzoic acid (PABA),
benzylidene camphor, butyl methoxy dibenzoyl methane,
diethanolamine p-methoxycinnamate, dioxybenzone, ethyl
dihydroxypropyl (PABA), glyceryl aminobenzoate, homomenthyl
salicylate, isopropyl dibenzoyl methane, lawsone and
dihydroxyacetone, menthyl anthranilate, methyl anthranilate, methyl
benzylidene camphor, octocrylene, octyl dimethyl (PABA), octyl
methoxycinnamate, oxybenzone, 2-phenylbenzimidazole-5-sulfonic
acid, red petrolatum, sulisobenzone, titanium dioxide,
triethanolamine salicylate, zinc oxide, and mixtures thereof
Especially preferred examples of these sunscreens include those
selected from the group consisting of
4-N,N-(2-ethylhexyl)methylaminobenzoic acid ester of
2,4-dihydroxybenzophenone, 4-N,N-(2-ethylhexyl)methylaminobenzoic
acid ester with 4-hydroxydibenzoylmethane,
4-N,N-(2-ethylhexyl)-methylaminobenzoic acid ester of
2-hydroxy-4-(2-hydroxyethoxy)benzophenone,
4-N,N-(2-ethylhexyl)-methylaminobenzoic acid ester of
4-(2-hydroxyethoxy)dibenzoylmethane, and mixtures thereof.
Exact amounts of sunscreens which can be employed will vary
depending upon the sunscreen chosen and the desired Sun Protection
Factor (SPF) to be achieved. SPF is a commonly used measure of
photoprotection of a sunscreen against erythema. See Federal
Register, Vol. 43, No. 166, pp. 38206 38269, Aug. 25, 1978, which
is incorporated herein by reference in its entirety.
Anti-Itch Ingredients
Anti-itch ingredients can be included in the controlled released
system of the present invention. Non-limiting examples of anti-itch
ingredients which are useful in the compositions of the present
invention are those selected from the group consisting of Stimu-tex
(available from Pentapharm); Takanal (available from
Ikeda-Distributer); Ichthyol (available from International
Sourcing-Distributor); Oxygenated Glyceryl Triesters (available
from Seporgia) and mixtures thereof.
Antioxidants
The controlled release system of the invention can also contain
other antioxidants including those well known in the art.
Representative antioxidants include vitamin E, tocopheryl acetate,
betaglucan, coenzyme Q10, representative formula
CH.sub.3C.sub.6(O).sub.2(OCH.sub.3).sub.2)CH.sub.2CH:C(CH.sub.3)CH.sub.2!-
.sub.nH, butylated hydroxy toluene (BHT), butylated hydroxy anisole
BHA, superoxide dismutose, propylgallate, and the like.
Skin Conditioners
The controlled release system of the present invention can also
contain other skin conditioners, moisturizers and surfactants can
be included as additives. Illustrative conditioners include mineral
oil, petrolatum, vegetable oils (such as soybean or maleated
soybean oil), dimethicone, dimethicone copolyol, cationic monomers
and polymers (such as guar hydroxypropyl trimonium chloride and
distearyl dimethyl ammonium chloride) as well as combinations
thereof. Illustrative moisturizers are polyols such as sorbitol,
glycerin, propylene glycol, ethylene glycol, polyethylene glycol,
polypropylene glycol, 1,3-butane diol, hexylene glycol, isoprene
glycol, xylitol, fructose and mixtures thereof.
Fragrances
A fragrance can be included in the controlled release carrier
system of the present invention. The fragrance that can be
encapsulated in the carrier system of the present invention can be
any odoriferous material and can be selected according to the
desires of the fragrance creator. In general terms, such fragrance
materials are characterized by a vapor pressure below atmospheric
pressure at ambient temperatures. The high boiling perfume
materials employed herein will most often be solids at ambient
temperatures, but also can include high boiling liquids. A wide
variety of chemicals are known for perfumery uses, including
materials such as aldehydes, ketones, esters, and the like. More
commonly, naturally occurring plant and animal oils and exudates
comprising complex mixtures of various chemical components are
known for use as fragrances, and such materials can be used herein.
Fragrances useful for the present invention can be a single aroma
chemical, relatively simple in their composition, or can comprise
highly sophisticated, complex mixtures of natural and synthetic
chemical components, all chosen to provide any desired odor.
Suitable fragrance which can be used in the present invention
comprise, for example the high boiling components of woody/earthy
bases containing exotic materials such as sandalwood oil, civet,
patchouli oil, and the like. The perfumes herein can be of a light,
floral fragrance, such as for example, high boiling components of
rose extract, violet extract, and the like. The perfumes herein can
be formulated to provide desirable fruity odors, such as for
example lime, lemon, orange, and the like. The perfume can be any
material of appropriate chemical and physical properties which
exudes a pleasant or otherwise desirable odor when applied to skin.
Perfume materials suitable for use in the present invention are
described more fully in S. Arctander, Perfume Flavors and
Chemicals, Vols. I and II, Aurthor, Montclair, N.J. and the Merck
Index, 8th Edition, Merck & Co., Inc. Rahway, N.J. both
references being incorporated herein by reference.
VI. Processing Method
VI.A. Nanospheres
The encapsulated active agent in the nanospheres of the present
invention can be prepared by the steps of (1) heating hydrophobic
materials to a temperature above the melting point to form a melt,
(2) dissolving or dispersing at least one of an active agent
fragrance in the melt, (3) dissolving or dispersing a conditioning
agent in the melt, (4) emulsifying the melt in the aqueous phase;
and (5) cooling the dispersion to ambient temperature to form a
fine suspension.
A fragrance or other active ingredients can be incorporated into
the hydrophobic solid nanospheres. Preferably, about 1% to about
80% of and more preferably about 1% to about 60% by weight of the
active agents are used in forming the nanospheres.
VI.B. Microspheres
The controlled release system of the present invention can be
prepared by the steps of (a) incorporating a conditioning agent, a
fragrance, and optionally other active agents into the hydrophobic
interior of the nanospheres, (b) forming an aqueous mixture
comprising the nanospheres and optionally one or more active
agents, a same or different fragrance, the cationic charge booster
and a water sensitive material, and (c) spray drying the mixture of
the present invention to form a dry powder composition.
Accordingly, the nanospheres can be encapsulated into the
microsphere structure. One or more of the active agents which can
be the same or different than the active agents incorporated in the
nanosphere can be incorporated into the microsphere structure.
A process for producing the multi component controlled release
system includes the following steps:
(i) heating a hydrophobic material to a temperature above the
melting point to form a melt;
(ii) dissolving or dispersing a cationic conditioning agent into
the melt;
(iii) dissolving or dispersing a first active agent and fragrance
into the melt;
(iii) dissolving or dispersing a second active agent and fragrance,
a cationic charge booster, and a water sensitive materials, such
as, starch derivative, hydrocolloid, natural gums, polyvinyl
alcohol, or mixture of thereof, in the aqueous phase and heating it
to above the melting temperature of the hydrophobic material;
(iv) mixing the hot melt with the aqueous phase to form an
dispersion;
(v) high shear homogenization of the dispersion at a temperature
above the melting temperature until a homogeneous fine dispersion
is obtained having a sphere size of from about 1 microns to about 2
microns;
(vi) cooling the dispersion to ambient temperature; and
(vii) spray drying the emulsified mixed suspension to form a dry
powder composition.
Homogenization can be accomplished in any suitable fashion with a
variety of mixers known in the art such as simple paddle or ribbon
mixers although other mixers, such as ribbon or plow blenders, drum
agglomerators, and high shear mixers may be used. Suitable
equipment for this process include a model Rannie 100 lab
homogenizer available from APV Gaulin Inc. Everett, Mass., a rotor
stator high shear mixer available from Silverson Machines, of East
Long Meadow, Mass., or Scott Processing Equipment Corp. of Sparta,
N.J., and other high shear mixers.
The suspension is spray dried to remove the excess water. Spray
drying is well known in the art and been used commercially in many
applications, including foods where the core material is a
flavoring oil and cosmetics where the core material is a fragrance
oil. Cf. Balassa, "Microencapsulation in the Food Industry", CRC
Critical Review Journal in Food Technology, July 1971, pp 245 265;
Barreto, "Spray Dried Perfumes for Specialties, Soap and Chemical
Specialties", December 1966; Maleeny, Spray Dried Perfumes, Soap
and San Chem, January 1958, pp. 135 et seq.; Flinn and Nack,
"Advances in Microencapsulation Techniques", Batelle Technical
Review, Vo. 16, No. 2, pp. 2 8 (1967); U.S. Pat. Nos. 5,525,367;
and 5,417,153 which are incorporated herein as references.
In one embodiment microspheres are formed by mixing nanospheres
incorporating a selected active agent with polyvinyl alcohol, or
compositions of polyvinyl alcohol and polysaccharides, under
conditions sufficient to encapsulate the nanospheres. Preferably
mixing a selected active agent with the polyvinyl alcohol, or
compositions of polyvinyl alcohol and polysaccharides, until the
emulsion is formed and then spray drying the emulsion to thereby
form an encapsulated nanosphere. In the preferred embodiment, the
moisture sensitive matrix is formed of a polyvinyl alcohol material
at a level from about 1% to about 80%, preferably from about 1% to
about 70% by weight of the matrix material with the balance being
the amount by weight of active agents and an optimal amount of
polysaccharides. In an alternate embodiment, the polyvinyl alcohol
is present in the matrix material in an amount of about 1% to about
80% and the weight of the polysaccharides are present in the amount
of about 1% to about 80%. In the preferred embodiment, the active
agent composition is generally present at a level from about 0.01%
to about 80% preferably from about 1% to about 50% by weight of the
encapsulated active agent with the balance being the polyvinyl
alcohol or polyvinyl alcohol and polysaccharides. Optionally other
conventional ingredients known in the art such as preservatives,
surfactants, can be used in accordance with the teachings of the
present invention. The multi-component spheres of the present
invention preferably have size of from about 0.5 micron to about
300 microns, more preferably from about 1 micron to about 200
microns, most preferably from about 2 microns to about 50 microns.
The present invention preferably has minimal active agents on the
surface of the spheres, preferably less than 1%.
Polyvinyl alcohol is an excellent barrier material to the
permeation of the volatile fragrance ingredients, and as a result
the controlled release systems of the present invention do not
provide perceptible odor in the dry state. Upon wetting by a
sufficient amount of aqueous fluid such as a body fluid, the matrix
can either dissolve to provide a burst of the active ingredients,
or swell and soften the matrix to slowly release the encapsulated
active agents over an extended period of time, depending on the
composition of the matrix, such as the ratio of polyvinyl alcohol
to other matrix materials. The use of moisture activated spheres
which provide varying rates of diffusion are contemplated. For
example, the moisture activated spheres may diffuse at any of the
rates of the following:
(i) at steady-state or zero-order release rate in which there is a
substantially continuous release per unit of time;
(ii) a first-order release rate in which the rate of release
declines towards zero with time; and
(iii) a delayed release in which the initial rate is slow, but then
increases with time.
It has been found that a greater amount of polyvinyl alcohol in the
matrix provides slower release rate as compared to a matrix
including a lesser amount of polyvinyl alcohol in combination with
a polysaccharide. For example, a matrix having about 70% to about
80% polyvinyl alcohol has a slower release rate than a matrix
having about 30% to about 40% polysaccharide and about 40% to about
50% polyvinyl alcohol. For example, if a high amount of polyvinyl
alcohol is used in the matrix, such as in the range of about 70% to
about 80%, the matrix provides controlled release of the active
agent over an extended period of time from the time the matrix
contacts moisture up to forty-eight hours. If polyvinyl alcohol is
combined with polysaccharide in the matrix, such as in the amount
of 30% to about 40% polyvinyl alcohol and 30% to about 40% of
polysaccharide, a greater amount of active agent is released upon
contract with moisture to provide a "burst" of the active agent and
the active agent is released over a shorter period of time for
example from the time the matrix contacts the fluid up to the range
of about 6 hours to about twenty-four hours. Typically, the active
agent at the surface of the sphere can be released upon contact
with the fluid with the remainder of the active agent being either
released in a burst if the matrix dissolves or over an extended
period of time upon swelling and softening of the matrix.
Nanospheres formed of a hydrophobic material provide a controlled
release system in order to release the active agent over an
extended period of time by molecular diffusion. Active agents in
the hydrophobic matrix of the nanospheres can be released by
transient diffusion. The theoretical early and late time
approximation of the release rate of the active ingredients
dissolved in the hydrophobic matrix of the nanospheres can be
calculated from the following equations: Early time approximation
(m.sub.t/m.sub.sec)<0.4
.infin..times..times..PI..times..times..times.d.infin.d.times..PI..times.-
.times..times. ##EQU00001## Late time approximation
(m.sub.t/m.sub..infin.)>0.6
.infin..times..function..times..times.d.infin.d.times..times..function..t-
imes..times. ##EQU00002## wherein: r is the radius of the cylinder,
m.infin. is the amount fragrance released from the controlled
release system after infinite time; m.sub.t is the amount fragrance
released from the controlled release system after time t; and
D.sub.p is the diffusion coefficient of the fragrance or aroma
chemical in the matrix.
The release rate for releasing the active agents from the
hydrophobic nanospheres is typically slower than the release rate
for releasing active agent from the moisture sensitive matrix. The
active agents can be selected to be incorporated into either the
hydrophobic nanospheres or the moisture sensitive matrix depending
on the desired time for release of the active agents. For example,
a predetermined first active agent can be incorporated in the
moisture sensitive matrix to be released upon wash and a
predetermined second active agent can be incorporated in the
hydrophobic nanospheres for release over an extended period of time
during or after the first agent has been released. For example, the
moisture sensitive matrix formed in accordance with the present
invention can release the first active agent upon contact with
moisture to provide a "burst" with continued release of the first
active agent and nanospheres formed in accordance with the present
invention can release the active agent depending on the release
rate from an initial time such as within few hours, up to a period
of few weeks.
The invention can be further illustrated by the following examples
thereof, although it will be understood that these examples are
included merely for purposes of illustration and are not intended
to limit the scope of the invention unless otherwise specifically
indicated. All percentages, ratios, and parts herein, in the
Specification, Examples, and claims, are by weight and are
approximations unless otherwise stated.
PREPARATION OF CONTROLLED RELEASE SYSTEMS FOR SOAPS
EXAMPLE 1
The following procedure is used for the preparation of a controlled
release system that provides enhanced deposition of a fragrance
transition and vitamin E on the skin and sustains their release
over an extended period of time. A floral fragrance and vitamin E
are encapsulated in the hydrophobic nanospheres. Incroquat
behenyl.RTM. HE (behenamidopropyl hydroxyethyl dimonium,
commercially available from Croda Inc.) is used as a cationic
conditioning agent in the hydrophobic nanospheres and the cationic
charge booster incorporated in the water sensitive microsphere is
polyethyleneimine having an average molecular weight of 1800,
commercially available from BASF Corporation under the trade name
LUPASOL.TM. PR815. The nanospheres hydrophobic matrix is candelilla
wax, commercially available from Strahl & Pitsch Inc. of West
Babylon, N.Y. The microsphere water sensitive matrix is Hi-Cap.TM.
100 (commercially available from the National Starch and Chemical
Company of Bridgewater, N.J.).
100 grams of candelilla wax is placed in an oven at 80 degrees
.degree. C. and allowed to melt. 1500 grams of deionized water are
placed into 1 gallon vessel, fitted with an all-purpose silicon
rubber heater (Cole-Palmer Instrument Company). 500 grams of
Hi-Cap.TM.100 (commercially available from the National Starch and
Chemical Company of Bridgewater, N.J.) was added to the water and
the aqueous solution is heated to 90 degree C. while mixing it with
a propeller mixer. The candelilla wax is removed from the oven and
300 grams of floral fragrance (commercially available from Noville
Inc. of South Hackensack, N.J.) and 50 grams of vitamin E
(commercially available from JEEN International Corporation of
Little Falls, N.J.) are mixed into the melt by hand with a glass
rod. 40 grams of incroquat behenyl HE (commercially available from
Croda Inc.) are also added to the melt. The fragrance/vitamin E/wax
mixture is poured into the aqueous solution and the dispersion and
10 grams of LUPASOL.TM. PR815 commercially available from BASF
Corporation are homogenized at 20,000 psi using a Rannie 100 lab
homogenizer available from APV Gaulin Inc. The dispersion is cooled
to ambient temperature by passing it through a tube-in-tube heat
exchanger (Model 00413, Exergy Inc. Hanson Mass.) to form a
suspension. The resulting suspension is spray dried with a Bowen
Lab Model Drier (at Spray-Tek of Middlesex, N.J.) utilizing 250
c.f.m of air with an inlet temperature of 380.degree. F., and
outlet temperature of 225.degree. F. and a wheel speed of 45,000
r.p.m to produce a free flowing, dry powder, consisting of 30%
floral fragrance and 5% vitamin E encapsulated in the solid
hydrophobic nanospheres.
EXAMPLE 2
The following procedure is used for the preparation of a controlled
release system that provides fragrance transition (powder floral to
mint) as well as delivers jojoba oil for extended period of time.
Menthol and jojoba oil are encapsulated in the hydrophobic
nanospheres and a powder floral fragrance is encapsulated in the
water sensitive microsphere. The nanospheres hydrophobic matrix is
Ganex.RTM. V-220 (commercially available from the ISP Technologies
Inc, of Wayne, N.J.). The microsphere water sensitive matrix is
Hi-Cap.TM. 100 (commercially available from the National Starch and
Chemical Company of Bridgewater, N.J.).
100 grams of Ganex.RTM. V-220 (commercially available from the ISP
Technologies Inc, of Wayne, N.J.) and 50 grams of incroquat
behenyl.RTM.l HE (behenamidopropyl hydroxyethyl dimonium,
commercially available from Croda Inc.) are placed in an oven at 60
degrees C. and allowed to melt. 1500 grams of deionized water are
placed into 1 gallon vessel, fitted with an all-purpose silicon
rubber heater (Cole-Palmer Instrument Company). 450 grams of
Hi-Cap.TM. 100 (commercially available from the National Starch and
Chemical Company of Bridgewater, N.J.) was added to the water and
the aqueous solution is heated to 90 degree C. while mixing it with
a propeller mixer. Ganex.RTM. V-220 is removed from the oven and 50
grams of Menthol (commercially available from Noville Inc. of South
Hackensack, N.J.) and 50 grams of jojoba oil (commercially
available from JEEN International Corporation of Little Falls,
N.J.) are mixed into the melt by hand with a glass rod. The
menthol/jojoba oil/Ganex.RTM. V-220 mixture is poured into the
aqueous solution and the dispersion and 300 grams of a powder
floral fragrance (commercially available from Noville Inc. of South
Hackensack, N.J.) are homogenized at 20,000 psi using a Rannie 100
lab homogenizer available from APV Gaulin Inc. The dispersion is
cooled to ambient temperature by passing it through a tube-in-tube
heat exchanger (Model 00413, Exergy Inc. Hanson Mass.) to form a
suspension. The resulting suspension is spray dried with a Bowen
Lab Model Drier (at Spray-Tek of Middlesex, N.J.) utilizing 250
c.f.m of air with an inlet temperature of 380.degree. F., and
outlet temperature of 225.degree. F. and a wheel speed of 45,000
r.p.m to produce a free flowing, dry powder, consisting of 5%
menthol and 5% jojoba oil encapsulated in the solid hydrophobic
nanospheres. The controlled release system obtained contains 5%
menthol and 5% jojoba oil, 10% Ganex.RTM. V-220, 5% incroquat
behenyl HE, 30% powder floral fragrance, and 45% water sensitive
material.
EXAMPLE 3
The following procedure is used for the preparation of a controlled
release system that encapsulates the same fragrance in both the
solid hydrophobic nanospheres and the water sensitive microsphere
to provide both fragrance "burst" in response to moisture as well
as extend fragrance release over a prolonged period of time. The
nanospheres hydrophobic matrix is Ganex.RTM. V-220 (commercially
available from the ISP Technologies Inc, of Wayne, N.J.). The
microsphere water sensitive matrix is Hi-Cap.TM. 100 (commercially
available from the National Starch and Chemical Company of
Bridgewater, N.J.).
200 grams of Ganex.RTM. V-220 (commercially available from the ISP
Technologies Inc, of Wayne, N.J.) and 50 grams of incroquat
behenyl.RTM. HE (behenamidopropyl hydroxyethyl dimonium, a cationic
conditioning agent, commercially available from Croda Inc.) are
placed in an oven at 60.degree. C. and allowed to melt. 1500 grams
of deionized water are placed into 1 gallon vessel, fitted with an
all-purpose silicon rubber heater (Cole-Palmer Instrument Company).
450 grams of Hi-Cap.TM. 100 (commercially available from the
National Starch and Chemical Company of Bridgewater, N.J.) was
added to the water and the aqueous solution is heated to 90.degree.
C. while mixing it with a propeller mixer. The Ganex.RTM. V-220 and
cationic conditioning agent are removed from the oven and 100 grams
of green fragrance (commercially available from Noville Inc. of
South Hackensack, N.J.) is mixed into the melt by hand with a glass
rod. The fragrance/Ganex.RTM. V-220 mixture is poured into the
aqueous solution and the dispersion and 200 grams of a green
fragrance (commercially available from Noville Inc. of South
Hackensack, N.J.) are homogenized at 20,000 psi using a Rannie 100
lab homogenizer available from APV Gaulin Inc. The dispersion is
cooled to ambient temperature by passing it through a tube-in-tube
heat exchanger (Model 00413, Exergy Inc. Hanson Mass.) to form a
suspension. The resulting suspension is spray dried with a Bowen
Lab Model Drier (at Spray-Tek of Middlesex, N.J.) utilizing 250
c.f.m of air with an inlet temperature of 380.degree. F., and
outlet temperature of 225.degree. F. and a wheel speed of 45,000
r.p.m to produce a free flowing, dry powder, consisting of 10%
green fragrance encapsulated in the solid hydrophobic nanospheres.
The controlled release system obtained contains 10% green fragrance
in the nanospheres, 20% Ganex.RTM. V-220, 5% incroquat behenyl.RTM.
HE, 20% green fragrance in the microspheres, and 45% water
sensitive material.
INCORPORATION OF THE CONTROLLED RELEASE SYSTEM IN SOAP PRODUCTS
EXAMPLE 4
Toilet soaps containing 1% neat fragrance was prepared by mixing 1
gram of the neat green fragrance oil with the soap base followed by
milling the mixture to create a soap bar. A toilet soap bar
comprising the encapsulated (Example 3) green fragrance was
prepared by mixing 3.3 grams of the powder of example 3 with the
soap base and creating a soap bar.
The ability of the soap bar to provide fragrance "burst" upon wash
as well as long lasting fragrance residue on skin following aging
the samples for one month at 45.degree. C. was evaluated by washing
hands with the two types of soap prepared, i.e., a control sample
comprising the neat oil and the experimental sample comprising the
encapsulated fragrance of Example 3.
TABLE-US-00001 Fragrance Intensity Upon Wash Neat Fragrance
(Control) 2 Encapsulated Fragrance 5
The results clearly indicate the controlled release system of the
present invention has the ability to retain the fragrance during
storage and release it upon need in response to moisture, during
wash.
TABLE-US-00002 Fragrance Intensity on Skin Following Wash 2 Hours 8
Hours Neat Fragrance (Control) 3 1 Encapsulated Fragrance 7 4
These results show that skin washed with the control sample,
comprising the neat fragrance, had very low odor intensity. The
skin washed the soap bar comprising the encapsulated fragrance had
higher odor intensity and odor intensity of the skin washed the
soap bar comprising the encapsulated fragrance, 8 hours after wash,
was significantly higher than that washed with the control sample.
Thus, the controlled release system of the present invention
sustains the release of the fragrance over an extended period of
time.
It is to be understood that the above-described embodiments are
illustrative of only a few of the many possible specific
embodiments which can represent applications of the principles of
the invention. Numerous and varied other arrangements can be
readily devised in accordance with these principles by those
skilled in the art without departing from the spirit and scope of
the invention.
* * * * *